On Oct. 7, the Lower Providence zoning board ended a months-long dispute by denying the NPCA's appeal of the ordinance, which permits a large complex that will include the museum, a hotel and conference center, and parking lots for 700 cars.
At the time, Tom Daly, then president and chief executive officer of the American Revolution Center, which owns the land and wants to build the museum, said he hoped the opponents would not take any further legal action.
A spokeswoman for the center said no one was available to comment on the lawsuit.
The goal of the NPCA "is not to be litigious, but to protect the park," said Joy Oakes, its senior director.
"That could be done much more quickly if people are open to a dialogue and at looking at options," she said.
But the suit may drag out the bitter fight, which has gone on longer than the Continental Army's brutal encampment.
Oakes said she could not predict how long it would take the suit - and its inevitable appeals - to wind through the courts, but "there's a sense of possibility in the air with the recent elections and various changes all over the place."
NPCA is a nonprofit group devoted to supporting and protecting the national park system.
The group is not against a museum at Valley Forge, just the proposed location, said Oakes. A better site, it says, is near the visitor center.
That was the original site for a museum to be built by the National Park Service and authorized by Congress in 1999.
The NPCA maintains that location is preferable since it is already developed and has been used for other purposes - including a limestone quarry and asbestos manufacturing - making it less pristine than the ARC site.
"Who could object to a museum to the American Revolution?" asked Oakes. "What is objectionable is that it's being proposed on land that is just as significant to the story of the American Revolution as any land inside Valley Forge national park."
Contact staff writer Kathy Boccella at 610-313-8123 or firstname.lastname@example.org.